NEW YORK (CBSNewYork) — A man shot a security officer who later died, and then took his own life, at a federal office building in the Hudson Square area Friday, police said.

As CBS2’s Alice Gainer reported, the shooting happened at 5:05 p.m., in the West Houston Street entrance to the federal office building at 201 Varick St.

The suspect walked into the building and approached the metal detector at the security screening area, NYPD Chief of Department James O’Neill said. The suspect then pulled out a gun and shot the security guard in the head, officials said.

The building houses a Department of Veterans Affairs office, a U.S. Post Office, The National Urban Security Technology Laboratory, and an Immigration Court, among several other offices.

As CBS2’s Tony Aiello reported, landlords in neighboring buildings made public address announcements as the situation full of fear and uncertainty unfolded. Tenants were warned of possible danger.

“We were just told to stay in the building,” said nearby worker Nick Fraccaro of Crown Heights.

“It was pretty scary,” said Margaret Serrano of Brooklyn Heights. “It was terrifying.”

Serrano said people near the entrance of nearby 225 Varick St. ran for cover moments after the gunfire.

“Everybody in the office was looking out the window. We weren’t able to see anything,” Serrano said. “A family on the street actually ran into our office.”

Downing is a former federal employee and had once been employed by the Bureau of Labor Statistics, according to NYPD Deputy Commissioner of Intelligence and Counter-Terrorism John Miller. There was also indication that he was a veteran, Miller said.

Police say Kevin Downing shot and killed a security guard at the federal office building at 201 Varick St., and then shot and killed himself, on Friday, Aug. 21. (Credit: CBS2)

His residence in Fort Lee was secured, Miller said.

Police said Camara was a private security officer who was shot was employed by the federal government. Camara worked for FJC Security Services and was represented by Service Employees International Union Local 32BJ.

Security officer Idrissa Camara was shot and killed at the federal office building on Varick Street on Friday, Aug. 21. (Credit: CBS2)

“We are shocked and horrified at this terrible news and send our deepest condolences to Protective Officer Camara’s family. Security officers around the city and country serve on the front line each and every day to keep us safe and secure. We are heartbroken that one of our own has fallen,” the union said in a statement. “We hope some of our questions in the face of this terrible tragedy will be answered. For now, we are keeping Officer Camara’s family and loved ones in our thoughts and prayers.”

Camara was armed at the time of the shooting, FJC Security said. He had been scheduled to finish the day at 4 p.m., but had stayed on for extra duty.

Camara was described as a devoted family man whose own father died just a few months ago.

U.S. Homeland Security Secretary Jeh Johnson was on the scene Friday night after learning the officer was killed.

“I hope to have the opportunity to express condolences to the family sometime this evening. It’s obviously a tragedy when anyone like this is killed in the line of duty,” Johnson said.

Police were working closely with the FBI, the Department of Homeland Security and other authorities to determine the suspect’s motive, O’Neill said. Police were also trying to determine whether the suspect had another target beyond the security officer, O’Neill said.

There was no indication of any connections to terrorism, O’Neill said.

There were no other suspects, and the building was secured after being placed on lockdown and later evacuated.